Numerical Solution of the Crown Forest Fires Spread Taking into Account Fire Barriers and Breaks

Abstract

AbstractUsing the method of mathematical modeling, the process of the emergence and spread of crown forest fires, as well as their termination in the presence of fire breaks and barriers, consisting of deciduous species, is studied. The Reynolds equations for turbulent flow were solved numerically, taking into account chemical reactions. The research was based on numerical solution of two dimensional Reynolds equations. The boundary-value problem is solved numerically using the method of splitting according to physical processes. A discrete analogue for the system of equations was obtained by means of the control volume method. The distributions of the fields of velocity, temperature, oxygen concentrations, volatile products of pyrolysis, combustion, and volume fractions of the condensed phase are obtained with time. The model made it possible to obtain in dynamics the contours of the spread of crown forest fires, which depend on the bulk and type of forest combustible materials, moisture content, wind speed and direction, etc. It was also possible to determine the dependence of the size of fire breaks and barriers on the above parameters, at which the crown fire stops spreading. Based on this data, we can estimate the minimum sizes of fire breaks and barriers, or their combined application, to stop the propagation of the flame front.